I would really think that unless it was a rear position, they would not be hiding any money -- Here in Georgia the lines were very fluid and if you consider that on Christmas of 1863 there were in Tenn and by Christmas of 1864 had marched through south to Atlanta , held up there and then went in Sept ( if my mind serves right ) left Atlanta and marched to Savannah ( about 300 miles, I do not think they were in one place very long,
Also this was a war and I doubt many would consider going back to PICK UP what they had left , They all ( either side ) just wanted it over and to go home.
Now a stash from a raided plantation might be a different story ,
I would look for " rear " positions , supply centers, railroad hubs, where those who were assigned there might hide stuff but as for " the infantry ground pounders " I don't think you would find any large hoards Good Luck